Case heater



NOV- 2j4 1925 w. H. WELSH CASE HEATER Filed Nov. 22, 1922 VN i,

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Patented Nov., 24, 19250.

unirti application fusa November 22, ieee.

To all whom t may concern:

Be it known that I, VJILLIAM H. VVnLsri, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented 5 a Case I-lleater, of which the following is a specification.

As one step in making electrotypes by a well known process, a metal plate coated with suitable molding material is forcibly pressed against the engraving, type, etc. from which the electrotype is to be made and the impression so made thereafter has copper, nickel, or other metal electrolytically deposited upon it so as to reproduce the snrface formation of said engraving, type, etc. from which the impression was originally formed. Y

ln operating this process I have found that the best, and most perfect impressions are formed in the molding material when the outer portions of said'mate-rial adjacent its exposed face are softer or less resistant to the passage of the type or engravings into said material than are those portions of the latter further removed from said surface, and one object of my invention is to provide a device whereby the outer portion of the molding material on a case or wax covered plate may be softened by heating while the deeper portions of said coating are retained in a relatively harder condition by being kept cool, so that the wait covered plate or the molding material on a case when applied to type, engravings, or the like, will ol'ier an increasing resistance to penetration by the latter' under the action of a suitable press.

A further object of my invention is to pro vide a relatively simple, compactfand convenient device for raising the temperature of the face of a case so as to soften the material thereon while simultaneously cooling the opposite side or back thereof so as to' maintain in a relatively hard condition the deeper portions of said material.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in which,

Fig. 1 is a front elevation of a case heater constructed in accordance with my invention; Y

Fig. 2 is a horizontal section on the line 2 2, Fig. l; and

caen Haaren, f

Serial ."rlo. 602,590.

Figs. 3 and l are vertical sections taken respectively on the lines 3-3 and @-4, Fig. 2.

ln the above drawings, 1 `represents an outer casing preferably of wood and in the form of a relatively flat box rectangular in vert-ical as well as in horizontal section. TWithin this is mounted a second casing 2, likewise of wood, and between it and said outer casing is a layer of such material as asbestos, magnesia, or cellular vegetable or mineral substances, constituting a lagging of material 3 which is a relatively poor conductor of heat. Both casings are open at one end and have a door l whereby said opening may be closed, this door fitting closely into the casings and having hinges 5-5 along its bottom edge.

Mounted within the inner casing 2 are two flat metallic containers G and 7, spaced apart to form a chamber 8 for the reception of a Y case to be heated, there being angle or other suitable brackets 9 suitably supported from the side walls of the inner casing, whereby the container 6 is held up and spaced away from the top surface of the container 7. While l have shown said containers G and Y as of tlatrectangular form, their shape and even their positions may be widely varied without departing from my invention which, so far as these elements are concerned, contemplates the provision of two independent containers spaced apart to provide a flat chamber between them for the reception of a case.

In accordance with my invention each of the containers 6 and Z has a baille or partition 10 extending from one end thereof to within a short distance of the opposite end, whereby they are divided into two chambers separated by a relatively narrow passage 11. The upper container 6 has respectively connected to its two chambers a pair of pipes 12 and 13 to permit of the delivery thereto of steam, hot water or other heating fluid which enters by a pipe 12 for example and passes out through the pipe 13. |The container 7 likewise has a central partition 141 dividing it into two chambers through which cold water or other cooling fluid is circulated from a supply pipe 15 to a discharge pipe 16.

A suitable lock or latch device 17 is provided for keeping the door l in its closed position and under conditions of use steam is supplied to the container G and cold Water to the container 7. rllhe case is thereupon introduced into the chamber 8 so that the back thereof rests upon or is slightlt7 raised from the flat top face of the container 7, its molding;` face being uppermost and exposed to the action of heat radiated or carried by convection from thelower face of the steam heated container' (S. rihe door e is thereupon closed and the plate is allowed to remain inv the heater for a suitable period7 such for example as one minute, more or less, according to the space between upper or molding side of the case and the bottom of the steam heated container (i, until the material atand adjacent the molding` surface of the case has appreciably softened. Owing however to the fact that the back of the case is in Contact or nearly so with the relativelycold top face of the water cooled container 7, the deeper portions of the molding material or those adjacent the face of the bod;Y of the case are maintained cool and' therefore relativelyv hard.

As a result, when the case Ytreated as above is placed with its molding face in contact With, the engraving' or type from Which an in'ipression is desired and is thereafter subjected to the action of a suitable press7 the type or engraving at first freely enters the molding material but meets a progressivelyv increasing resistance therefrom owing to the fact that while its superficial portions are soft, its deeper portions are hard. As a consequence the impressions received by the inoldin material are true and perfect so that the electrotyge plates ultin'iatelg.r formed therefrom faithfully reproduce in the most satisfactor;7 manner the finest portions of eng-raving. lait' tone plates and the like.

claim:

l. The herein described method of making electrotjv'je plates, which comprises the covering' of a metallic plate with molding` material to forni a case softening the outer surface of the moldingl material by heatingl` maintaining' the deeper portions of said molding material ina relativelf,Y harder condition b v keeping the saine coolj and subsequentl)T olacingv the softened molding` material in Contact with the engraving or type from which the impression is to be made.

The herein described method of making` electrotype platesl` which comprises the covering` of a suitable inetallie plate with inoldin material to forni a case, placing` the case in a container having an upper heating` surface wherebyv the outer surface of the case is soltened and lower cooling; surface r\,'iei'e,b}' the deeper portions of the case are maintained in a relatively hard condition, and subsequently placing the treated case in contact with an engraving` or type and applying pressure to the same7 whereby the ease so treated Will offer an increasing resistance to the penetration of the engraving or type.

VVLLIM H. WTELSH. 

